Crane with pneumatically extensible gantry mast



June 1965 R. J. BUSHONG ETAL 3, 8 ,906

CRANE WITH PNEUMATICALLY EXTENSIBLE GANTRY MAST Filed Jan. 25, 1963 4 SheetsSheet 1 FIG. 1'

KI'TORPEYS JIIM 1965 R. J. BUSHONG ETAL 3,

CRANE WITH PNEUMATICALLY EXTENSIBLE GANTRY MAST Filed Jan. 25, 1963 4 Sheets-Sheet 2 V TORS @afia VIRGIL F. KRAMER ATTORNEYS R BERT GEORG June 1955 R. J. BUSHONG ETAL 3,

CRANE WITH PNEUMATICALLY EXTENSIBLE GANTRY MAST Filed Jan. 25. 1963 4 Sheets-Shee t 4 2 mgm i gg o BY vl n f nausea ammagmmuy ATTORNEYS sisrass CRANE wrrrr rrsnnrvrairrearrr nxrnnsrsrn GANTRY MASK" Robert I. Bushong, Vermilion, George 6. Neil, North.

Ridgeville, and Virgil F. Kramer, Elyria, Ghio, assignors, by mesne. assignments, to Koehring Company, Miiwaulree, Wis, a cerporation of Wisconsin FiledJanZS, 1963', Sen'No. 253,948 "7 Claims. Ci. Z12-'-59) This invention relates. generally, as indicated, to aireamass Patented dune 1%65 tact with the machinery A-frame regardless of the mounting of the boom on such frame. p

Yet another object is the employment of boom stop springs which" can be compressed and then releasedto assist the movement of the boom frorn a position of maximum elevation.

Other objects and advantages of the present invention will become apparent as the following description protractible mast and boom-stop andrmo re particularly to certain improvements in the highly'mobile crane iIICOTPQ-r rating the-features of both a retractible mast and a boom stop as disclosed in the cop'ending application of Robert J. Bushon'g et al.,Serial No. 105,145, filed April 24,1961,

entitled Retractible Mast and Boom Stop, now Patent In power cranes, shovels and the like, masts areenv.

' ployed to obtain a high angle of incidence between the boom pendants and the boom thereby to .obt'ainmaximu'm litting capacities. WhenJsuchcranes are 'rnounted on a 7 truck -incarrier ichassis for highway movement, the mast is still employed-to supportfthe boominitsjtravel posi tion, but such generally constitutes an obstacle inthat the mast exceeds the overall height of; the machine" and the machine will thus not --clear highway bridges, overhead wires and the like; -Accordingly, themast must be retractedifor' highway travel andextended for crane opi cation. in such prior copending, application; heavy rela "tively' expensive spring mechanisms areemployed to ex; tend themast to working positionand considerable pull on the "d'errickin'g l cables is-required to compress such spring -rnechanisrn -to telescope the. relatively movable mastfsection toretract the same for highway travel. =With the present invention, the telescoping ofgthe mast can be i l accomplished by the pull of the derrickinglineswith little V or no resistance and the mast may beextended to Working position without the afOrementi nedheaVy spring mechi Moreover, with the present invention,- mechanicalhoom stops .carriedby'theb'oom and guided by the mast are provided which will; contact the machinery A-framelimiting the upward movement or" thebo'om. Such boom stops.

' are'provided' with spring cushioned end sections which will produce an increasing resistancejto the elevation of theboom as it approaches its maximum elevated position.

Thesefshock absorbcrsnot' onlycushion'the elevation of :"the boor nbut absorb undue shockloading.

absorbed by these spring cushions canalso ibeernployed The 'force,

to move the boom from; its position of maximum eleva-l tion. Finally, the mounting ofthe -boom stops on the theig;antry mast extendedg'f j I 1 .1216. 3 is afragmentary side elevation sirnila'rto FIGS. i 7 1 andZ illustrating the position ofthe gantry-,mast and-1 boom stop in the maximumposition' of elevation of. the

ceeds;

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described andparticularly pointed out in the claims, the following description and the annexed drawings setting forth indetail a certain illustrative embodi-l ment of the invention, this being indicative, however, of but oneof the variousways in which the principle of the invention may be employed.

In said annexed drawings:

FIG; 1 is aside elevation of a rubber tired carrier mounted crane in accordance with th'e prese'n't invention a frontlend ofthe carrier j with the boom extendinglover the in highway travel position- FIG. 2 is a'i'side elevation of the crane lwith bloom;

4 is an enlargedftragmentary top plan detail M view partially broken away ofthe retractible gantryrnast and boom stop; 7 FIG. 5 is mast with the boorn stop broken away; 7 I

- 7 FIG. 6 is a detail sectional view ofthe end of the'boomstop taken substantially on the line 6+6 of FIG. ,4;

' PEG/7 is an enlarged fragmentary detail view partially broken away of the -proxinralend of thegantry mast structure; and i H FIG. '8 isa. fragmentarydetail view of the telescoping members of one of the boom stops lbroken away illus trating. the spring cushion mechanism therein.

Referring now to the annexed drawings and more pari: ticular'ly to FIGS. 1, Zand 3,there'- is illustrated a crane.

in accordance with the present invention. In FIG. 1,

the gantry mast is shownretracted' and the boom in a substantially horizontal travelling position," In "FIG; 2, the gantry mast is shown extended withthe boom still in its substantially horizontal position. FIGQB shows the f Such crane comprises a chassis or truck carrier frame mast issuch that the-boom can be mounted at different positions on the'machinery frame, and such cushioned echanical stopping of the boom can still be obtained. I

- Itis accordinglya principal object of the present in boomstop. ,7 a

Itis another; main} object to provide a simplifiedretr actible mast for cranes and the like-enabling such crane more quickly and easily to he prepared for; highway travel.

Still .another main object is the provisionot such a retractible mast for cranes and the like which can very simply be extended to working position. v

A further object is the provision of a retractible gantry mast for cranesand-the like which can beextended by vention to provide a retractible mast fora crane and the' I like incorporating therein a mechanical spring loaded" fluid pressure and retracted by the boom derricking lines.

Q A still further object is the provision of a retractible gantry mast for cranes and the like which will adjustably support a positive boom stop guiding theisame into .con-.

gantry rn-astexten-ded, theboom in'its maximum posisuperstructure.

tion of elevation, and the boom stops 'engagingthecrane T'mounted on rubber'tired wheels 22which are driven by a prime mover in compartment 3 which can b eoper ated from cab 4 at the front of the chassis framef [The frontwheels are also steered from such a cab to provide r therequisite highway mobility for the crane carrier; Mounted on the bed ofthe chassis frame is a turntable 5 which supports acrane'superstructuregenerally. shown at 6 for revolving movement about the vertical axis of such turntable. Outriggers 7 and 8, of the typ'eiprefe'rably including curved outrigger beams which maybe ex: tended laterallyof the frame 1 by means of hydraulic. "piston-cylinder assemblies, are mounted on the chassis frame 1 to provide a wider and firmer operating base sup port for the turntable 5 and the crane superstructure 6 mounted thereon.

The turntable bed 10 of the: superstructure 6 is providedv at its forward end with a boom foot'll towhich is pivotally mounted at 12 the foot of boom 13. As shown in FIGS. 1 and 2, such boom 13 comprises a base section 14 and a peak section 15 pin-connected together as at 16.

a fragmentary side elevation of such gantry ricking line 19 is wrapped around such drum and extends I about a reeving ina harness Ztland about similar reev ing in a harness 21 mounted on the distal end of retractible gantry mast 22. V 7

Such gantry mast 22 is pivoted to the back or the boom base section 14 as indicated at 23. Boom pendants 24 connect the harness 21 at the peak of the gantry mast and the peak frame member 25 on the peak of the boom 13 as shown at 26. The boom derricking line then extends from the drum 18 about a sheave in the harness 26, then about asheave in theharness 21 and back about a sheave and 68 are flared as shown at 75 and 76 and support a transverse axle 77 for the sheaves of harness 21 by means of removable caps 78 and 79.

As seen perhaps more clearly in FIG. 7, the inner ends of each of the inner tubes 67 and 68 are closed by means of an end plate 80 having a central aperture 81. Through such aperture there is provided a spacer pin 82held on the inner side of the end plate 86 by a cotter pin 83. The

in the harness 28 and then back about a sheave in the T harnessZl', etc., and is anchored on. one or the other harness. Thus a pull on the derricking cable will movethe harnesses 2t) and 21 toward eacliother exerting a pull on theboom pendants 24 which in turn exerts a pull on thepeak of the boom pivot. 12. Y

The harness 20, which may include asmariy as four to elevate the boom about its foot or sheaves for the boom derricking line 19, is mounted at v vthe peak of an A-frame 30 the crane superstructure 6 and such superstructure includes two spaced boom stop contact members 31 adapted to engage the distal ends 32' and 33 of'boom stops 34 and 35. Such boom stop memhers-34 and 35 are connected to a strap or plate 36 which is secured about the upper portion of the base section 14 of the boom 13. Each of the boom stop members comprises telescoping inner and outer tubular members 37 and 38 with the outer member 38 being slide guided in trunnions 39 and 46 mounted on special brackets on the gantry mastZZ. Thus both the boom stop members and the gantry mast are pivotally connected to the boom base s'ection' andboth will'be' elevated and lowered with the boom. -A counterweight 41 is positioned at the back of the A-frame and such will counterbalance the weight of the boom, mast and stop assembly, and the load carried thereby about the axis of the turntable 5.

Referring now to FIGS. 4, 5 and 7, it will be seen that the gantry mast 22 may comprise a bottom section 45 comprised oftwo parallel 6 inch O.D. tubes 46 and 47,, approximately 9 feet,.;3 incheslong. Such outer bottom tubes are interconnected by transverse tubing 48 and 49 with gusset plates 50 and 51 being employed with the latter to rigidify the entire bottom section 45. The lower ends of such tubes 46 and 47 are closed by circular end plates 53 and 54 to which are secured projecting apertured plates 55 and 56, respectively, accommodating pins 57 and 58 which are employed with cotter pins 59 to pinconnectthe proximal end of the retractible gantry mast to a the top of the boom basefs'ection 14 near the boom foot 11.

The transverse tubular framing member 48 at the dis-v tal ends of the tubes 46 and 47 extends between collars 61'and 62 which enclose the upper ends of such tubes.

The upper or movable section 69 of the retractible gantry mast comprisesessentially the inner tubular members 67 and 68 which are joined together by a tubular cross brace 72 connecting angularly inwardly directed portions 73 and 74 of such tubes 67 and 68 respectively.

The :outermore closely spaced distal ends ofthe tubes 67 The bushings then provide and 47. Lockingpins lll may then be inserted through" pin 82 is welded to a plate 84 which is in turnsecured by screws 85 to a follower cup 86. The screws 85 may be wire-locked together as shown at 87. Held between the plate 84 and the follower cup is an annular sliding packing 88. The end of the tube 68 is recessed to accommodate a bushing '89 providing a sliding bearing support for the inner end ofthe tube '68 within the outer tube 47. A relatively short stop tube 98 is secured to the end plate 54 limiting the inward movement of the tube and packing assembly with respect to the outer'tube. The structure of the inner tube 67 within the tube 46 will be exactly the same as that shown in connection with the tubes 68 and 47.

Each of theend plates 53 and 54 is provided with'a tapped 'air aperture in which are'secured' a T 92 and a fitting 93,-respectively. The Tvand fitting are interconnected by a length of .air tubing 94 which,'as seen in FIG; 4, extends along the outside of the tube 46 and across the tubular brace49, being held thereto by clamps 95, and then along the tube 47 to the fitting 93. Secured to the T 92 is an elbow 96 whichinturn has secured thereto a quick-disconnect coupling 97. 1

As seen in FIGS. 1, 2 and 3, an inflation hose 98 may be connected to such coupling; 97- and such hose extends to a valve 99 of the three-way type,;i.e., open, closed,

exhaust, which is in turn connected by air tubing-100 to air reservoir 101. The carrier air reservoir tanks 101 will normally be employed to provide the air pressure require to extend the gantry mast 22 and it will be understood that the valve 99' may be situated in the operators cab 102, as shown, or may be provided on the carrier itself. When thevalve is situated in the operators cab 102, the

line 100 will normally extend through'a rotary seal in the turntable 5. It can now be seen that the operator can quickly supply the proximal end of the retractible gantry mast with air under pressure, at preferably about 90 pounds per square inch, by simple manipulation of the valve 99, and this air pressure will be suflicientto cause the outer section ofthe mast 69 to telescope outwardly of the inner section 45;

As the air pressure forces out the upper mast section 69, the operator will pay outthe derricking cable 19 until holes 105 and 106 in the innertubes 67 and 68 are aligned with holes 109 and 110 in each of the outer sections '46 such aligned apertures. Such locking pins will preferably be held in place by lock washers, cotter pins, or the like and the gantry mast 22 is thus locked in its extended position'. The mast will havethen moved from the FIG. 1

disconnected from the coupling 97. I,

to the FIG. 2 position as the derricking cable 19 'is payed out. The derricking cable can nowbe operated to raise the gantry mast and boom to the working position. The valve 99 may then be turned to exhaust the air within the tubes 46 and 47 to atmosphere and the hose 98 may be To place the booms 13 in a travel position, this is ac complished simply by lowering the boom 13 to a horizontal position on supports or with the boom peak 25 resting on the ground G. This can be done over the side or rear of the carrier. The operator then slacks ofi on the derricking cable 19 until the mast 22 rests on the boom and the pendants and cables are slack. The hose 98 is then connected to the'coupling 97, the valve 99 being closed.

The operator then removes both locking pins 111 and commences to pay in the dern'cking line 19. The force Q I highway travel.

. If it is desired to travel ftion, the abovefsteps are, of course reversed. When the mast 22 is'parallel to'theboom base section then mayset valve 39 either toreturn air to' the reservoir 101 or to exhaust air to atmosphere. Continued-reeling in of the derricking cable 19 will not only retract the upper mast section, but will also .take up the slack in'the pendants 24.. 'When' suchslack is taken up, the boom will then be picked up and at the proper height may be swung to travel positionadjacent the carrier cab' as seen in FIG, 1. @Whenin such travel position, the'retracted mast 22, as seen in FIG. 1, will not project above the normal height of the boom and crane superstructure to con- .stitute an obstruction for highway travel.. The inflat-ion hose 98 can then be removed and the crane ready for with the base section of the boomonly, the boom can be lowered to supports or the ground as in' the preceding procedure. The derricking 3 insert an erecting pin through lifting eyes 115 on the base boomi section and through apertures inthe distal then be'pin-locked to the base boomsection 14 and the operator may employ the derricking cable 19 to raise cation of Erwin C. Brekelbaum et al., entitled FCrane, V Serial No. 211,282; filed July 20, 1962, for a disclosure w of such towerboom adapter. This will require a corresponding shifting of the position of thetrunnions 39 and 40 on the mast structure 22 so that the boom stop fitips 32 and 33 will contact the back stops 31 of the .may" be adjusted with respect to the pivot 23 and thus with respect to the boom foot pivot 12 properly to cause the boom stops toengage the back stops 31'as the boom cable 19 is payed out to lower the fullyextended and t a locked mast structure torestl on top of the boom base section. Supports 114- on hubs s1 and 62 are provided] properly to space the mastand boom.- The operator will then remove all ,of thetop sections of the boom and, t the appurtenant ,bompendants The operator may then 'A-frame. For'example'the boom stop pivot point may be in theoutermost aperture 137*when the boom is hinged on a tower boomadapter. In any event, the location of. the boom stop guides or trunnions' 39 and is elevated.

As seen in FIG. 8, each of the boom stops 34 and 35 is comprised of inner and outer telescoping tubular members with a spring 140 being interposed between l the 'end 141 of the-innerv member S S and an annular block or plug 142 within the outer member 37. Screws 143 may be "employed to hold the block 142 longitudinally stationary within the outer tube 37. Although I only one is shown in FIG. 8, itis preferred that three v be employed firmlyvto hold. the block 14 2 in the tube 37 The inner tube 38 is retained within the outer tube by means of a rod 145 which extends through and is welded to the end 141 of? the inner tube38. Such rod, extends through the spring 143 and freely through, an

the boom base section to travel height and then swing l the assembly into travel position; To return to opera 14, the derrickingcable 19 passingabout the sheaves in projects from both ends of the brac'kets supporting rollers A further elongated roller 126 is mounted on bushings 127 in turn mounted on shaft 12% extending between shaft supports 129and 130 mounted on the exterior tubul'ar frame members 46 and .47, respectively, of the inner 'mast section .45. The shaft 123 may be held in such supports by" screws 131 and grease fittings 132 are provided to lubricate the bushing zshlaft bearing surface." I The roller126 together'with the four rollers 124- serve tov deflect the derricking cable 19 when the mast 22 is subs'tantially horizontal) Brackets 135 and 13 5 are secured to the outside ofthe hubs 51 and 62 and projectlongitudinally outwardly along 'the outer tubular portions, 75 ,and 76 of the outer mast section 69. As seen in FIG. 6; the sectional configuration ofthe brackets 135and 136 is in the form of a channel beam with the flanges extending inwardly or toward each other.- Each channel shape bracket is'provided-with four equally spaced apertures 137 as shown in FIG. 5.

the pivot pins 1328for trunnions or boom stop guides 39 and 41). Such pins maybe held in place bykeepers 14%); When the crane is'in operation, the trunnion or -boom stop guides 39 and 40 will be mounted a fixed'distance from the pivot 23 on the top of the room base sectioml l. These will serve to guide or float the boom stops 34 and {35 into A-frame contact position at the position of maximum boom elevation.

Anyone of these apertures may serve as the mounting for a For some cranes, however, it may be desirable toema 1 Thus, as seen in Pros.

aperture 146 in the center 'of block 14-2. The end of the rod. .145 projecting through*the aperture 146 is.

threaded andipr'ovided with a stop nut 148 which will a limit the movement ofthe innertube 38 with respect to the' .oute'rtube 37. Such stop nut will," however, not,

preclude the inner tubeifrom telescopingwithin the, outer tube against the compression of springlltlg- The p'roxi m'al'ehd of eachof the outer tubu1'arfmembe rsf37 is closedand provided with an'eye plate 149 which is then connected by pins150 to elevi'se's 151 and'152jon1the top of the strap orplate 35 mounted onthe top of the boom base section 14.

from the boom foot pivot 12,into mechanical engage- The spring loaded tips of the boom stops not only act as cushions absorbing undue shock :as the boom reaches its position of maximum elevation, but they also provide an increasing resilient pressure which will, of course, beat maximum when the boom is in maximum elevation position. Also, it has been found that with rctractible gantry masts and boom stops of the type shown herein, the center of gravity of the boom assembly may actually move beyond thevertical plane of the V pivot 12 retaining the boom in-its maximum position of 1 elevation requiring an external force to pivot the center of gravity back beyond the vertical plane 'of the" pivot 12. Thus the operator may employ the compressed force of-the springs 14010 assist in moving the boom structure in-a counterclockwise direction as seen inFIG. 3. By reeling in the derricking cable 19, the spring Will, of course, be compressed and by releasing such derrisking cable the compressed springs will tend to pivot or initially move the boom and mast assembly in a counterclockwise direction about the pivot 12 until the center of gravity moves beyond the vertical plane of the pivot 12; Accordingly, the springs 14-0 not only serve as cushions, but also as a means to store energy which can then be applied when the derricking cable 19 l is released to pivot the boom structure in a counterclockwise direction about the boom foot pivot 12.

With the present invention, it has been found that crane capacities can be markedly increased by means of 1, 2 and 3, the boorn stops 34 and 35 will be slide-guided through the trunnions-39 t 1 and E4} which are pivoted on the mast 22 a fixed distance said follower cup; 1

i, 4. The combination ofc'laim 3 in which said end plate t a gantry and back stop assembly whichcan very easily be erected and lowered-by the use of the machine air system and theoperation of the derricking cable.

'Oth'er modes of applying the principle of the invention may-be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

We,, therefore, particularly point out and distinctly claim as our invention: 1, In combinatioma frame, a boom pivoted to said frame for vertical swinging movement about a horizontal axis, a fluid pressure reti'actible and extensible gantry mast pivotally connected to said boom, hoisting means connected to the peak of said mast for vertically swinging said mast and 'thus said boom, and a source of air under pressure connected to said mast to extend said mast and whereby said hoisting means is adapted for retracting said mast thereby renewing said source of air under pressure. 7 s 2. .The combination of claim 1 in which said mast comprises telescoping inner ando'uter sections with sliding seal means interconnecting said inner and outer sections, and valve means connecting said source of air to said outer mast section, whereby opening of said valve means will supply air under pressure to said outer section to force said inner section longitudinallyoutwardly section of said .ma'stis' closed by an endplate, a fol lower cup is secured to said end plate, and an annular packing means is positioned between said end plate and is provided with an air aperture, a coupling'is attached 8 1 are provided in said mast for locking such, in its extended position.

7 in combination, a trame, a boom pivoted to said frame for vertical swinging movementabouta horizontal axis, a mast pivotally connected to said boom, a trunnion mounted on said mast a fixed, distance from such mast-boom pivot, pendants interconnecting the peak of said mast and the peak of saidboom, hoisting means connected to the peak of said mast for vertically swingbers telescoped one within ,the other and a compression spring interposed between and connected to said tubular members resiliently urging said inner tubular.

member to maximum extended position, said stop mernber engaging said framea'nd compressing said spring on maximum elevation of said boom, said mast includ ing telescopinginner and outer sections, a source of air under pressure for extendi ng said mast, valve means connecting saidsource ofyair to said outer mast section, and slidingflseal means interconnecting said inner.

v and outer mastsectionawhereby opening of said valve to said aperture, and an air hose is connected to said" coupling to supply air to sa'idvalve means." 5. The combination of claim 2 in which s'aid'valve means is adapted to supply air for extending said 'rnast, to return air to said'air source and to exhaust air to the atmosphere.

6. The combination'of claim Zin which locking means ANDRES 'NIELSEN f means will supply air under pressure to said outer section to force said inner section longitudinally outwardly thereof and whereby saidhoisting means is adapted for} retracting said mast thereby-renewingsaid source of air under pressure. i I

References Cited by Examiner I t g UNITED STATES PATENTS; v 917,992 4/19 Baked-a1.' -91 470, 1,768,267 /30 Phillips 1685;: 1,947,524 2/341 Horldt 16-8f5,1" 2,509,686 5/50 Huston 1 21 2 '-59. 1, 2,627,985 2/53 Sathre'et a1. 212' 59.-1

40 SAMUEL F. COLEMAN, Primary Examiner.

Bush o n'g et al. 212 59.'1v 

1. IN COMBINATION, A FRAME, A BOOM PIVOTED TO SAID FRAME FOR VERTICAL SWINGING MOVEMENT ABOUT A HORIZONTAL AXIS, A FLUID PRESSURE RETRACTIBLE AND EXTENSIBLE GANTRY MAST PIVOTALLY CONNECTED TO SAID BOOM, HOISTING MEANS CONNECTED TO THE PEAK OF SAID MAST FOR VERTICALLY SWINGING SAID MAST AND THUS SAID BOOM, AND A SOURCE OF AIR UNDER PRESSURE CONNECTED TO SAID MAST TO EXTEND SAID MAST AND WHEREBY SAID HOISTING MEANS IS ADAPTED FOR RETRACTING SAID MUST THEREBY RENEWING SAID SOURCE OF AIR UNDER PRESSURE. 